In his late teens, Adam Yauch – “MCA” of the Beastie Boys – did not look the type to be an effective rapper. When they met for the first time, Darryl McDaniels of Run-DMC suspected that he might be an actor put up by the TV show Candid Camera. How else could he account for a white performer who, along with his bandmates Mike “Mike D” Diamond and Adam “Ad-Rock” Horovitz, coupled the carefree character of punk with the clownish one-upmanship of hip-hop?

Yet though McDaniels was apprehensive about their first tour date together, in front of an all-black audience in Georgia in 1986, “the crowd loved them, because they weren’t trying to be black rappers… Real recognises real.” Starting from their own experience made Yauch, Diamond and Horovitz white rap stars, with eight albums selling a total of more than 40m copies in a career that lasted for a quarter of a century. Yauch has died of cancer at the age of 47.

Thanks in large part to his husky voice, dry humour and enlightened political outlook, fans moved on from the band’s early declared enthusiam for beer and pornography to appreciate their sharp satire and pop sophistication. Away from the microphone, Yauch made films and videos, and was a Buddhist supporter of Tibet. Everything he did was accomplished with disarming integrity.

Born in Brooklyn, New York, to Noel Yauch, an architect, and his wife Frances, a schools administrator, Adam was inspired to form a band after seeing the hardcore punk band Black Flag. The Beastie Boys – also including his high-school friend Diamond at the start – performed their first concert on Yauch’s 17th birthday, with him on bass guitar. A year later they recorded an eight-song EP, but then broke up.

While he was studying at Bard College, 90 miles to the north, Yauch developed a new line-up, the hip-hop trio with Diamond and Horovitz, and then dropped out after two years of his course. Their debut rap record, Cooky Puss, came in 1983.

Though little more than a syncopated phone prank with some rock guitar, this brought them to the attention of the rap-label boss and producer Rick Rubin. He added AC/DC-style riffs to the Beasties’ cocky lyrics, and secured them a support slot on Madonna’s 1985 Like a Virgin tour.

Their stage set, which included a 20ft hydraulic penis, drew tabloid press coverage, and their pairing of guitars with rap lyrics gave them access to radio play on suburban rock stations. Having again begun as something of a prank, the band’s first album, Licensed to Ill (1986), went on to become the fastest-selling debut release in Columbia Records’ history, selling more than 750,000 copies within its first six weeks and topping the Billboard chart. The hit single from it, (You Gotta) Fight for Your Right (to Party), served as a rallying cry for the young and rowdy everywhere.

Following label disagreements, the band briefly relocated to Los Angeles, recording Paul’s Boutique (1989) there. Though commercially less successful, this heavily textured album allowed the trio to shake off their juvenile reputation.

Gone were the macho party lyrics like “Like a lemon to a lime a lime to a lemon, I sip the def ale with all the fly women” from No Sleep Till Brooklyn, on Licensed to Ill. On their single Sure Shot, from Ill Communication (1994), Yauch acknowledged he had “more rhymes than I’ve got grey hairs, and that’s a lot because I’ve got my share”, while, in a later verse of the same song, he berated misogyny in rap with the lines “I want to say a little something that’s long overdue, the disrespect to women has got to be through. To all the mothers and the sisters and the wives and friends, I wanna offer my love and respect till the end.”

Yauch converted to Buddhism in the early 1990s, after travelling to Tibet and Nepal. Another track on Ill Communication has him rapping a Buddhist vow, and in 1994 he also co-founded the Milarepa Fund, to promote awareness of the unjust treatment of native Tibetans by the region’s Chinese occupiers.

The following year he met his wife, fellow activist Dechen Wangdu, at a talk given by the Dalai Lama at Harvard University. They married in 1998, in a traditional Tibetan ceremony, but with Yauch’s favourite hardcore punk band, Rancid, playing at the reception. Milarepa promoted a series of Tibetan Freedom Concerts, and marked the tenth anniversary of 9/11 by organising New Yorkers Against Violence in aid of victims of violence.

Under the name of Nathanial Hörnblowér, Yauch directed many of the band’s videos, including So What’cha Want (from the album Check Your Head, 1992) and Intergalactic (from Hello Nasty, 1998). In 2008, he co-founded Oscilloscope Laboratories, a film production and distribution company, responsible for releasing independent films such as that year’s Wendy and Lucy, and We Need to Talk About Kevin (2011).

Oscilloscope was also the vehicle through which Yauch filmed and released his documentary, Gunnin’ for That No 1 Spot (also 2008), following the stories of eight high-school basketball stars as they prepared to enter the professional sport. As he made clear to me in an interview for the Guardian, bringing out the financial, racial and regional differences between them – before they received the media training that went with endorsement contracts – was intended to give it a political edge.

At the time the Beasties’ eighth album was bogged down in remixes and multiple collaborations: eventually it saw the light of day as Hot Sauce Committee Part Two (2011), widely welcomed as a return to form. Their six albums up to and including To the 5 Boroughs had each sold at least 1m copies. The purely instrumental seventh, The Mix-up (2007), won a Grammy award.

Yauch was diagnosed with cancer in a salivary gland in July 2009, and was unable to attend the Beastie Boys’ induction into the Rock’n’Roll Hall of Fame last month. He is survived by Dechen, his daughter Tenzin Losel and his parents.

• Adam Nathaniel Yauch, musician and film-maker, born 5 August 1964; died 4 May 2012